Answer:
x ≈ 24.4
Explanation:
Since the 2 legs of the triangle are congruent, both 26, then the triangle is isosceles.
The line segment x is a perpendicular bisector and divides the isosceles triangle into 2 congruent right triangles, with base 18 ÷ 2 = 9
Using Pythagoras' identity in either of the 2 right triangles, then
x² + 9² = 26² , that is
x² + 81 = 676 ( subtract 81 from both sides )
x² = 595 ( take the square root of both sides )
x =
≈ 24.4 ( to the nearest tenth )